Story highlights

Bolton player collapsed during a match against Tottenham on Saturday evening

Muamba able to breathe without ventilator and respond appropriately to questions

Hospital treating the 23-year-old say long-term prognosis will remain unclear for some time

Soccer star Fabrice Muamba, who suffered a cardiac arrest on the field playing for Bolton Wanderers on Saturday, is able to breathe without a ventilator and respond to questions, according to the hospital treating him.

The 23-year-old collapsed at Tottenham Hotspur's White Hart Lane stadium in London during an English FA Cup quarterfinal game and was treated by paramedics on the pitch.

He was subsequently taken to the London Chest Hospital where he has been in a critical condition since Saturday evening.

But a joint statement released by the hospital and Bolton on Monday evening said Muamba's condition had marginally improved.

It read: "Fabrice Muamba is continuing to show signs of improvement this evening.

Photos:Tributes to Fabrice Muamba

Photos:Tributes to Fabrice Muamba

'Miraculous' Muamba – Doctors have described Fabrice Muamba's progress since his cardiac arrest during a match on Saturday as "miraculous." The Bolton star's heart stopped beating for 78 minutes after his collapse but now he is talking and joking with visitors.

Hide Caption

1 of 8

Photos:Tributes to Fabrice Muamba

Messi wishes Muamba well – Barcelona's Lionel Messi wore a t-shirt with a message of support for Muamba before Wednesday's game with Granada, in which the Argentina striker scored a hat-trick and became the club's leading goalscorer of all time.

Hide Caption

2 of 8

Photos:Tributes to Fabrice Muamba

Bolton to face Blackburn – Bolton announced Thursday they will fulfill their Premier League fixture with local rivals Blackburn on Saturday after postponing the midweek clash with Aston Villa. Before Blackburn's win over Sunderland on Wednesday their players offered messages of support for Muamba.

Hide Caption

3 of 8

Photos:Tributes to Fabrice Muamba

Fans pay tribute – Bolton Wanderers fans have left flowers and scarves outside the English club's Reebok Stadium in support of Muamba, while most of the playing squad have been to visit him in the London Chest Hospital.

Hide Caption

4 of 8

Photos:Tributes to Fabrice Muamba

Ex-teammate honors Muamba – Muamba's former teammate Gary Cahill, who left Bolton to join Chelsea in January, revealed a t-shirt honoring his ex-colleague after scoring against Leicester City on Sunday.

Hide Caption

5 of 8

Photos:Tributes to Fabrice Muamba

International support – Tributes were paid to Muamba from across the footballing world. Real Madrid's players took to the pitch before last Sunday's Spanish league match with Malaga wearing shirts displaying a message of support for the midfielder.

Hide Caption

6 of 8

Photos:Tributes to Fabrice Muamba

Best wishes – Fans at Liverpool's FA Cup quarterfinal against Stoke City send their best wishes to Muamba. Supporters also chanted his name at various points during Sunday's Anfield match.

Stunned supporters looked on as he was treated on the field while reports in the UK press claimed it took two hours for Muamba's heart to start beating normally again.

Referee Howard Webb abandoned the match after consultation with players and managers from both sides. Bolton's Premier League game with Aston Villa, scheduled for Tuesday, has also been called off.

Muamba's manager Owen Coyle has regularly visited the hospital where he is being treated, as have players from Bolton and other Premier League clubs.

Spanish club Real Madrid carried shirts that read "Get well soon Muamba" before their draw with Malaga on Sunday, and Coyle said the player's family were grateful for all the support they had received from around the globe.

"The message is the good will, the prayers from everybody, they are so thankful and they want to put that on record -- to say 'keep up the prayers, thanks for all the support,' " the Scot told reporters.

"They have been inundated as we all have, both in the football community globally and family and friends. People are taking a genuine interest and a real concern with how Fabrice is doing.

"It's a difficult situation but the family are bearing up as well as they can. They themselves are very positive people.

"You look at what Fabrice has been through in life already and you can tell that he is a fighter. He has such a fantastic smile and that's what we all want to see again."

Muamba's wife Shauna took to Twitter on Monday to say: "All your prayers are working people thank u so so much. Every prayer makes him stronger. "

There have been other cases of players collapsing during soccer matches. Motherwell's Phil O'Donnell suffered heart failure during a 2007 game against Scottish rivals Dundee United and died on the way to hospital.

The most high-profile tragedy of this kind came when Cameroon international Marc-Vivien Foe collapsed during a Confederations Cup semifinal against Colombia in 2003 and died in hospital.

There have been two similar incidents more recently in Spain, involving Sevilla's Antonio Puerta in 2007 and Espanyol's Daniel Jarque in 2009.